1. Field of the Invention
The invention relates to a fluid pump, in particular a high-pressure fuel pump, for internal combustion engines with direct injection, having a housing, a drive chamber in the housing, an eccentric shaft or camshaft disposed in at least some regions in the drive chamber, and at least one pumping element which can be set into a reciprocating motion at least indirectly by the eccentric shaft or camshaft.
2. Description of the Prior Art
A fluid pump of the type described above is known on the market, and is used as a high-pressure fuel pump and in internal combustion engines with fuel direct injection. In such engines, the fuel is first pumped to the high-pressure fuel pump by a prefeed pump. The high-pressure fuel pump then compresses the fuel to a very high pressure and pumps it onward to a fuel collection line, where the fuel is stored at very high pressure. Connected to the fuel collection line are a plurality of injectors, which are assigned one to each combustion chamber and inject the fuel directly into the combustion chambers.
The known high-pressure fuel pump is a multi-cylinder radial piston pump, whose pistons are driven by a camshaft. A camshaft is supported in a housing, and via roller tappets, it sets the pistons into a reciprocating motion. For lubricating the moving parts of the high-pressure fuel pump, this pump is connected to a pressurized lubricant circulation system of the engine. By means of a mounting flange, the lubricant oil can flow out of the high-pressure fuel pump back to the engine.
The present invention has the object of refining a fluid pump of the type defined at the outset in such a way that it has a longer service life.
In such a fluid pump this object is attained in that the drive chamber, in a region that in terms of the direction of rotation of the eccentric shaft or camshaft is ahead of the at least one pumping element, communicates with a lubricant relief region.